1920s-ish collage/painting

I just got my hands on this great little picture. It's a collage and painting over some George V stamps. That, combined with the state of the frame, pins and paper, I'm guessing it was made somewhere around the 1920s but I've no clue who the artist is and of course they didn't sign it. Any ideas?

The girl is based on Armand Marseille's German bisque 'gooly eyed' dolls, made famous in children's books by Mabel Lucy Attwell amongst others. Unfortunately, without a signature, I think this is just the work of a keen amateur artist. But very much of the period, which is nice :)

Thanks Naomi. So it looks like this isn't going to earn me millions then. Never mind, I'll keep hunting.